Molding articles containing inserts

ABSTRACT

A method and apparatus for mass-manufacturing elongated hollow plastic objects, such as covers for electronic thermometer probes, and ball point pens, having inserts at the ends thereof. The inserts are automatically loaded, by vibrating the same into pockets and then lifting them out of the pockets into suction tubes which pass through a horizontal transfer plate into nests in a vertical transfer plate. Vacuum is employed to maintain the inserts in the nests during movement of the vertical transfer plate to positions adjacent the distal ends of hollow core pins through which air is sucked. The vacuum in the vertical transfer plate is then converted to pressure to cause the inserts to fly across the air gaps to the core pin ends, following which the inserts are maintained on such ends by suction. The mold is then closed to cause the inserts to engage spring-biased plungers, following which the plastic is injected.

[451 June is, 1974 United States Patent 1 1 Van de Walker et al.

[54] MOLDING ARTICLES CONTAINING Primary Examiner-Robert o. SheridanAssistant Examiner-George F Abraham I INSERTS [75] Inventors: Roger D.Van de Walker; Blair E.

Attorney, Agent or Firm-Richard L. Gausewitz Howe, both of Costa Mesa,Calif.

ABSTRACT A method and apparatus for mass-manufacturing elongated hollowplastic objects, such as covers for elec- 5 .l 0 C m mfi m .m.. t z WM79 .m% o mCM I m w C N m .w d n .m A H N n W m tronic thermometer probes,and ball point pens, having inserts at the ends thereof. The inserts areautomatically loaded 211 App]. No: 309,451

ne momm kfi e CW WISH-1 fm w u nmu i m lV km. c e o pmh 0.

Related S Application Data by vibrating the same into and then liftingthem out of the [62] ?l.;/|lS9l03l'l96Of Ser. No. 79,191, Oct. 8, 1970,Pat. No. tubes which p through a hori into nests in a vertical transferm m 7QU R 32 2 l00 3 5 2 8 2 2 .SM 7 1 2 m, 5 H "M 4 W 2 2 WW3 WM H NW24 WHO 1 "3 2 m m m m L .f C lo S U I H UN 5 55 l [.1

lowing which the insertsare maintained on such ends References CitedUNITED STATES PATENTS by suction. The mold is then closed to cause theinserts to engage spring-biased plungers, following which the plastic isinjected.

3,588,149 6/1971 Demler 285/137 R X Krauer............................

2 Claims, 19 Drawing Figures A III 5 w m M PAIENTEDJun 18 m4 sum 2 or aMEANS WM Wm EN 7 PATENTEMmmn 3L81TL402 sum 3 or a fl a. .55

Pmzmemumm I A 313 171402 sum 5 (If a xix MOLDING ARTICLES CONTAININGINSERTS This is a division of application, Ser. No. 79,191, now U.S.PatiNo. 3,719,396 filedOct. 8, 1970.

BACKGROUND OF THE INVENTION and 2,896,250. In addition to such patents,the following US. Pat. Nos. disclose means for feeding inserts intoinjection molding machines: 2,518,850; 2,579,951; 3,018,519; 3,293,693;3,423,792.

The follwoing US. Pat. Nos. relate to the pneumatic feeding of articlesfor various purposes other than injection molding: 3,275,191; 3,410,607;3,448,236.

SUMMARY OF THE INVENTION Stated generally, one aspect of the inventionrelates to a relationship between pockets, combination gate and liftingfingers, vacuum passages and vibratoryfeeder means adapted toeffect-automatic loading of inverted cup-shaped inserts through suctiontubes into individual nests in a vertical transfer plate. In passingthrough the tubes into such nests, the inserts'travel through ahorizontal plate adapted to move horizontally between a position closelyadjacent the vertical transfer plate and a position spaced therefrom. Inaccordance with another aspect of the invention, the inserts are,maintained. in such nests by means of suction and during movement of thevertical transfer plate from a loading position to a discharge positionregistered with elongated hollow core pins. When the vertical transferplate is in discharge position, the inserts are propelled through theair across a space between the nests and the core pins, such propulsionbeing effected by an air blast applied to the nests. Air is suckedthrough the hollow core pins in order to provide combined effectsincluding cooling of such core pins, thus eliminating the need for watercooling, and maintaining the inserts on the core pin ends during closingof the mold. The inserts seat on biased piston elements adapted toprovide'sealing functions and also ejecting functions. I

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric viewschematically representing the injection molding machine, the transferplates associated therewith, and the means to supply inserts to suchtransfer plates and thus to the core pins in the molding machine, thevertical transfer plate being in its loading position above the molds;

FIG. 2 is a view, partially in side elevation and partially in verticalsection, showing the vertical transfer plate in its discharge positionbetween the mouths of the mold cavities and the distal ends of the corepins;

line 4-4 of FIG. 3, the vertical transfer plate being in its loadingposition, the horizontal transfer plate being spacedfrom the vertical;

FIG. 5 is a vertical sectional view corresponding gen erally to aportion of the central region of the showing of FIG. 2 but after thevertical transfer plate has moved upwardly from between the molds, saidfigure showing schematically the fluidics and the vacuum source;

FIG. 6 corresponds to FIG. 5 except that it shows the mold in closedcondition, the schematic showings of the vacuum source and the fluidicsbeing omitted;

FIG. 7 corresponds to FIGS. 5 and 6 but shows the parts in the strippingposition, the showings of the vacuumsource and fluidics being againomitted;

FIG. 8 is an enlarged view representing a core pin in longitudinalcentral section and in the position assumed immediately prior to seatingof an insert on the springbiased plunger;

FIG. 9 is a further enlarged, fragmentary view corresponding to theright portion of the showing of FIG. 8, but after the mold elements havecome fully together so that the insert is seated on the spring-biasedplunger;

FIG. 10 is an enlarged, fragmentary, horizontal sectional view showinghow the inserts are propelled through the air from their nests in thevertical transfer plate to seats on the distal ends of the core pins;

FIG. 11 is a horizontal sectional view showing schematically the valvemeans for effecting alternate application of vacuum and pressure to thenests in the vertical transfer plate;

FIG. 12 is a fragmentary sectional view corresponding to a left regionof FIG. 4 but showing the horizontal transfer plate after shiftingthereof to the position at;

which the tube ends seal around the nests in the vertical transferplate;

FIG. 13 is a vertical sectional view taken on line l3--l3 of FIG. 4,showing the manner of distribution of air to the nests in the verticaltransfer plate;

FIG. 14 is an exploded schematic view of the mold elements, the stripperplate being shown in stripping position;

FIG. 15 is an enlarged fragmentary view of the face of the female moldelement;

FIG. 16 is an enlarged fragmentary view, primarily in section, showingthe parting-line region of the mold when in closed condition;

FIG. 17 is a schematic representation of the vibratory supply (feedingand loading) means which is indicated in diagrammatic block form at theupper left portion of FIG. 1;

FIG. 18 is an enlarged fragmentary view of the supply means, partiallyin elevation and partially in section; and

FIG. 19 is a transverse sectional view on line 19-19 of FIG. 18.

GENERAL DESCRIPTION OF A PREFERRED EMBODIMENT Although it has variousother important uses, such as (for example) in the manufacture of ballpoint pens,

the present. method and apparatus will be described in connection withthe manufacture of elongated hollow covers20 (FIG. 7) for the probes(not shown) of electronic thermometers. Such electronic thermometers areadapted to determine the temperatures of patients in hospitals, etc., inan extremely short period of time and with digital instead of analogreadout. Prior to the taking of the temperature of each patient, one ofthe present covers 20 is mounted over the probe, following which a metalinsert 21 at the end of the probe cover is touched to the tongue of thepatient, following which the digital readout is noted and the probecover thrown away or recycled.

In the manufacture of such a product, and in the manufacture of otherproducts such as ball point pens, it is extremely important that thecycle time of the molding apparatus be minimized. With the presentmethod and apparatus, the cycle time in the mold may be reduced toapproximately seconds or less, which means that a l6-cavity mold mayproduce one of the present probe covers each second.

As best shown in FIG. 10, the inserts 21 are generally cup-shapedobjects each having a varying wall thickness. The wall thickness is suchas to make the inserts nose-heavy and very unstable, so that they tipover easily when fed along a vibratory surface as described relative toFIGS. 17-19. The varying wall thickness of each insert 21, and the cupshape thereof, are such as to tend to make the inserts fly through theair with their noses oriented forwardly instead of rearwardly.

Each insert 21 is very small and light. For example, each insert mayweigh 0.03 grams. The diameter of the rim or mouth portion of eachinsert may be 0.150 inch, whereas the length of each insert may be 0.175inch. The inserts are formed of aluminum.

Provided at the rim of each insert, as shown in FIG. 10, is a radiallyoutwardly extending bead or flange 22 adapted to be embedded in theplastic which is molded in manufacturing the probe cover 20. Theinterior wall of each insert 21 is generally conical, as indicated at23.

Such conical relationship tends to cause the inserts to Y stack and nestrelative to each other if they are not maintained separate at all times.After any such stacking it is very difficult to separate the insertsfrom each other.

The plastic body 24 (FIG. 7) of each probe cover 20 is generallytapered, the end of the probe cover remote from insert 21 being open.The body is provided with a step or shoulder at 25. The body 24 may beformed of a suitable molding material, namely a thermoplastic syntheticresin such as medium-impact styrene.

The apparatus employed for mass-manufacturing the probe covers 20includes an injection molding machine (press) which may be of variousconstructions. The injection molding press schematically illustrated inthe present drawings includes a fixed support 27 (mounted by suitablemeans, not shown) which is rigidly secured by tie bars 28 to thestationary platen 29 of the press. The moving platen 31 of the press isadapted to slide on the tie bars 28 when actuated by an actuating meanssuch as the hydraulic cylinder 32 shown in FIG. 1. Cylinder 32 has anassociated piston rod 33 (FIG. 2) which extends slidably through support27.

It is to be understood that the present showing is only schematic, andthat the cylinder 32 may actually comprise a more complex togglemechanism adapted to apply great pressures to the moving platen 31. Thecylinder 32 or other actuating means is suitably controlled by themolder control means represented in block form (FIG. 1) at 34.

The control means 34, like all of the control means schematicallyrepresented in the present application, preferably forms part of aunitary over-all control circuit which makes the entire operation fullyautomatic,

so that the operator merely stands by the machine and watches formalfunction. Since such over-all control circuit and mechanism form nopart of the present invention, and since the various control operationsfor the cylinder 32 and other portions of the apparatus may be performedby hand (as by the operators actuation of suitable valves and switches),no description of the over-all control circuit will be provided.

The side of the press incorporating the stationary platen 29 is normallythe hot side of the press." Such hot side incorporates the feed hopperfor the plastic, the heating means for the plastic, and the plasticextruder which forces hot plastic into the mold means describedhereinafter. Referring to the right side of FIG. 2, a portion of theextruder and associated nozzle is represented at 35. These elements areassociated with an injection control means represented in block form at36, such means determining the amount of plastic which is injected andalso determining the times of injection (preferably under the control ofthe over-all automatic control circuit indicated above).

A first (female) mold element 37 is fixedly mounted on the stationaryplaten 29, this being the element which defines the elongated parallelcavities 38 in which the probe covers 20 are molded. Such cavities havemouth portions 39 disposed remote from the stationary platen 29 andrespectively adapted to receive elongated core elements (core pins) 40.Such core elements or pins 40 are parallel to each other and areregistered with the cavities 38, being mounted in cantileveredrelationship on a second (male) mold element 41 which is rigidlysupported on the moving platen 31.

In the illustrated mold means 37-41 there are sixteen cavities, it beingunderstood that a greater or lesser number could be employedThe sixteencavities are provided in four vertical rows (FIG. 14) with four in eachrow. The mold 37 (and the ejector plate described below) are providedwith suitable means to conduct hot plastic from the extruder and nozzlemeans 35 (FIG. 2) to the various cavities 38. Such means includesrunners 42 (FIGS. 14-16) and tunnel gates 43.

The second or male mold element 41 is on the ejector side of the press(as distinguished from the hot side thereof). Such element 41 not onlymounts the core pins 40 but also mounts leader pins 44 adapted to beintroduced into bushings 45 (FIGS. 5-7) in mold element 37 in order tomaintain the molds in precisealignment.

The leader pins 44 perform the additional function of mounting insliding relationship a stripper plate 46 having openings therein throughwhich the core pins 40 project. The stripper plate 46 is operatedbetween a retracted position (FIG. 5) and an extended position (FIG. 7)by means of one or more cylinders 47 shown schematically in FIG. 2. Asuitable control means, indicated in block form at 49 in FIG. 2, isassociated with cylinders 47 in order to control the operation thereof.The stripper cylinders 47 are mounted on the moving platen 31, bysuitable means (not shown), and have rods which connect to plate 46.

Plate 46 operates not only as a stripper but as part of the mold means,since it closes the mouths of cavities 38 when the mold means are closedas shown in FIGS. 6 and 16. The openings in plate 46 then receive thecore elements 40 in very snug-fitting relationship.

In addition to the core pins 40 and leader pins 44 which are mounted incantilevered relationship on male mold element 41, puller pins 51 (FIG.16) are mounted thereon and extend slidably through corresponding boresin thestripper plate 46. The puller pins have tapered end portions 52which are provided with undercut grooves and which extend into certainregions of the runners 42 when the moldmeans are closed (FIG. 16).

In the operation of the apparatus as thus far described, and withoutreference to the various apparatus and mechanisms associated with theinserts 21, the hydraulic cylinder 32 (FIG. 1) is operated by controlmeans 34 to shift its piston rod 33 (FIG. 2) and thus movable platen3lto the right until core pins 40 are inserted into the elongated moldcavities 38 as shown in FIGS. 6 and 16. The stripper plate 46 is at thistime.

fully retracted, and operates (as described above) to close the mouths39 of cavities 38. The injection control means 36 (FIG. 2) then operatesto extrude hot plastic through extruder and nozzle means 35 into acentral port 53 (FIG. 14) in mold element 37. Thereafter, the plasticpasses through runners 42 in both the mold element 37 and the stripperplate 46 until it reaches the tunnel gates 43 (FIG. 16) and thus fillsthe cavities 38. The mold element 37 is then cooled by a suitable means,not shown, which effects shrinkage of the resulting hollow plasticarticles onto the core pins 40.

The molder control means 34 (FIG. 1) is then operated to pull the corepins 40 out of cavities 38 and to pull the undercut pin ends 52 (FIG.16) out of the mold element 37. Due to the undercut relationships at thepin ends 52, there is pulled from mold element 37 the solidified runnerportions shown at 54 in FIG. 14. Furthermore, the solidified hollowobjects (probe covers 20) move outwardly with the-core pins 40 (due tothe above-indicated shrinkage thereon) and also due to the operation ofspring-biased plungers described hereinafter.

The stripper control means 49 (FIG. 2) then operates the strippercylinders in such manner as to shift stripper plate 46 to the right,which strips the probe covers 20 from the core pins 40 as shown in FIG.7. The probe covers 20 and the runner 54 (FIG. 14) then drop into adischarge chute, not. shown. In the event there 'are any hangups,stripper means associated with the loader 56 (described hereinafter)positively actuated the elements down into the chute. During thedescribed ejector operations, the element 54 (FIG. 14) is severed fromthe probe covers 20 by shearing at the smalldiameter ends of the tunnelgates 43.

inserts will be present in the ends of the probe covers 20 as describedabove, includes five main components.

The first of such components is the loader, which is representedgenerally at 56 in FIGS. 1 and 2, and which includes components whichmove in and out from between the mold elements 37 and 41 in order toeffect seating of inserts 21 on the distal ends of core pins 40 prior tomolding. The second of such components is the means for applying vacuumor suction to the core pins 40 to draw air therethrough and therebyachieve two major results, namely: (a) cooling of the core pins in theabsence of water cooling to thereby greatly shorten the cycle time ofthe molding apparatus, and (b) maintenance of the inserts 21 in seatedpositions on the core pin ends after the inserts are shot through theair from components of the loader 56. Such vacuum means is indicatedschematically in various views, namely in FIG. 8 and FIG. 5, at 57.

The third of the indicated components is the plunger means 58 best shownat the right in FIG. 8 and also shown in FIG. 9. Such plunger means 58maintains the inserts 21 firmly seated on the distal ends of the corepins during molding, provides seals insuring that the plastic moldingmaterial will remain in the desired locations, aids in ejecting theprobe covers 20 from the mold 37, and'provides communication to thefluidic sensing apparatus indicated below.

The fourth of the indicated components is the fluidic sensing andcontrol means represented in block form at 59 in FIG. 5. Such means iscritically important to the achievement of high-speed molding operationswithout frequent stoppages and breakdowns, and is described and claimedin copending patent application, Ser. No. 79,174, filed Oct. 8, 1970,for Fluidic Sensing for Molding System, inventor Roger F. Etherington,now U.S. Pat. No. 3,677,680. The disclosure of such copending patentapplication is hereby incorporated by reference herein as though setforth in full. By use of the fluidics 59, it is assured that one andonly one insert 21 will be provided on each core pin 40 prior to mold-.ing, and it is also assured that each insert will be removed from themold element 37 subsequent to moldmg.

The fifth of the indicated components is the supply means representedschematically in block form at 61 in FIG. 1 and also at 61a in suchfigure. The supply means effect automatic feeding-of inserts 21 to theloader means 56, and are hereinafter described in detail with referenceto FIGS. 17-19 of the drawings.

The loader 56, the vacuum means including source 57, the plunger means58, and the supply means 61 and 61a are described in detail hereinafterunder separate subheadings, as are the methods associated with suchcomponents.

DETAILED DESCRIPTION OF LOADER 56 AND ASSOCIATED METHOD The loader 56comprises, as best shown in FIGS. 1 and 2, a vertical yoke 63 which isrigidly mounted on the upper surface of the first molding element 37.

Mounted in suspended relationship from the upper A vertical transferplate 69 is mounted for movement i from a loading position (FIG. 1)between bearing block 67 and the opposed wall of loader box 66, to adischarge position between the distal ends of core pins 40 and themouths 39 of cavities 38 (FIG. 2). To thus move the vertical transferplate 69 between its loading and discharge positions, vertically movableframes are provided and comprise vertical support members 70 to whichthe transfer plate 69 is secured, and vertical shafts 71 which arerigidly connected to the upper and lower ends of such support members70. The shafts 71 extend slidably through the bearing block 67 tothereby provide a rigid relationship assuring that the vertical transferplate 69 will be positioned precisely.

The upper ends of the vertically movable frames formed by elements 70and 71 are secured by a connector lug 72 to the upper end of piston rod65 for cylinder 64, whereby operation of the cylinder will raise andlower the transfer plate 69 as indicated. Suitable loader control means,indicated in block form at 73 in FIG. 1, are associated with thecylinder 64 and also with the pneumatic circuitry associated with thetransfer plate 69 and described hereinafter, to thereby control the sameas indicated below.

As shown in FIG. 2, the sizes of the vertically movable frames 70-71,and the size of the vertical transfer plate 69, are such that thisassembly may readily fit between mold element 37 and the core pin endswhen the mold is in the illustrated open condition. The outer face 75(FIGS. 2, 4 and of plate 69 is then spaced a substantial distance,namely approximately two-tenths inch, from the extreme distal ends ofcore pins 40. As described hereinafter, it is a feature of the inventionthat the inserts 21 are shot through the air gap across such space tothe core pin ends, thereby eliminating the necessity of causing thevertical transfer plate 69 to move horizontally at any time,particularly while it is present between the mold elements 37 and 41,with consequent decreases in the expense and complexity of the apparatusand in the cycle time.

Referring to FIGS. 1 and 2, stripper lugs or ears S are mounted at thelower ends of the described vertically movable frames. Such lugs are sopositioned that they move downwardly between the vertical rows of corepins 40, thereby assuring that the probe covers (FIG. 7) and runners 54(FIG. 14) will not hang up but will instead drop out of the press.

The loader apparatus 56 further comprises a horizontal transfer plate 76which is located in the vicinity of the vertical transfer plate 69 whenthe latter is at its loading station (FIGS. 1 and 4) within loader box66. Means are provided to move the horizontal transfer plate between afirst station spaced from the vertical transfer plate 69 as shown inFIG. 4, and at which there is no interference with movement of thevertical transfer plate into or out of the mold, and a second stationadjacent the face 75 of such plate. Such means include leader pins 77mounted on plate 76 and extending through suitable bushings in box 66 tothereby guide the plate 76. Such means further comprise compressionsprings 78 (FIG. 4) which are seated between box 66 and the heads ofscrews 79. Screws 79 extend slidably through clearance openings in box66 and are threaded into the plate 76. There is thus provided a biaswhich tends to maintain plate 76 in engagement with box 66 until theplate 76 is positively actuated toward plate 69.

The means for actuating horizontal transfer plate 76 away from theadjacent wall of box 66, and toward plate 69, includes an actuator pin81 which extends freely through an opening (FIG. 4) in box 66. Pin 81 isadapted to be engaged and shifted by a lug 82 on moving platen 31 whenthe mold moves toward closed condition. The positioning of lug 82 issuch that, when the mold is closed, horizontal transfer plate 76 isshifted sufficiently close to vertical transfer plate 69 that theextreme ends of suction tubes of conduits 83 will be in sealingengagement with surface of plate 69 and will enclose nests in such plate69, as shown in FIG. 12 and as described below.

Referring particularly to FIG. 12, and to the left side of FIG. 4, thesuction tubes 83 are plastic tubes the internal diameters of which aresufficiently large to slidably receive the inserts 21. The tubes 83extend inwardly through oversize openings 84 in box 66 and into fittings86 which are threaded into plate 76. The tubes 83 extend completelythrough the fittings 86 and through the plate 76, and extend a slightdistance from the inner surface of the plate 76 for sealing contact withsurface 75 of plate 69 as shown in FIG. 12. Because of the fact that theends of the tubes 83 protrude and sealingly engage surface 75 asdescribed, a relatively high suction may be drawn on the tubes 83 toeffectively move inserts 21 therethrough over a substantial distanceeither vertically or horizontally.

The suction tubes 83 extend to the insert supply means 61 and 61adescribed below relative to FIGS. 17-19, and schematically representedin FIG. 1, which supply means 61 and 61a are preferably located at eyelevel or therebelow and on the floor adjacent to the molding machine.Because the apparatus 6161a is vibratory in nature, and because theopening and closing of the press creates shock, it is important that themeans 61-6la be isolated from the press. Such isolation is effectivelyachieved by the tubes 83 which are the only connections between thesupply means and the other components of the press.

It is emphasized that the supply means 6161a may be located at a lowlevel, for example four feet below the loader box 66. This is to becontrasted with various types of apparatus wherein gravity is employedto effect feeding of inserts, so that the insert supply must be at ahigh and inconvenient level.

Since, in the presently illustrated apparatus, the mold employed is a16-cavity mold, there are sixteen tubes 83 extending from the loader 56to the supply means 61-61a. The ends of the tubes 83 remote from theloader are arranged in a row as described below, whereas the endsadjacent the loader are spaced and oriented correspondingly to thespacing and orientation of the core pins 40 and mold cavities 38.

Provided in the outer face 75 of the vertical transfer plate 69 are amultiplicity of seats or nests 88, FIGS. 4, 10 and 12, such seats ornests also serving as insertejecting means when plate 69 is in thedischarge position of FIG. 2. The seats or nests are orientedcorrespondingly to the ends of tubes 83, that is to say correspondinglyto the orientation of the core pins 40 and cavities 38.

As best shown in FIG. 10, each nest 88 is shaped to receive one insert21 in relatively loose, non-binding relationship, with the rim of theinsert 21 facing outwardly. Each nest 88 is sufficiently shallow thatthe rim of the'insert 21 seated therein is disposed a short distanceoutwardly from surface 75. The insert rim (when the insert is seated innest 88 as shown at the right in FIG. 10) is, for example, aboutthree-sixteenths inch from a plane which is perpendicular to the axis ofcore pin 40, and which contains the extreme end of such core pin.

The edge portion of each nest is rounded, as shown in FIG. 10, in orderto prevent damage to the inserts when they emerge from the suction tubes83.

Each. nest communicates through an elongated, relatively small-diameterpassage 89 with a manifold passage 91 formed in the vertical transferplate 69. The manifold passages 91, in turn, communicate through othermanifold passages'92 and 93 (FIG. 13) with a central port 95a leading toa two-way valve 95.

As schematically represented in FIG. 11, valve 95 includes a chamber 94which communicates through port 950 with the interconnected manifold andother passages. One end of such chamber 94 is connected to a source 95bof vacuum,'whereas the other end of such chamber is connected to source96 of pressure.

A double poppet 97 is movably mounted in the chamber 94 for actuation byan actuator 98 and an associated spring. The actuator is controlled by asuitable pilot which may form a part of the loader control means 73illustrated in block form in FIG. 1. The vacuum source 95!; is a sourceof relatively high vacuum, for example about 20 inches of mercury,whereas the pressure source is'a source of air pressure at approximately125 psi.

The controls for valve actuator 98 are so operated that, during thegreat majority of time, the double poppet 97 is in the illustratedposition permitting the vacuum source 95b to communicate with port 95aand thus with the associated passages. Thus, the relatively 'high vacuumis drawn on-the l6 passages 89 and on the nests 88 to maintain theinserts 21 seated in such nests as desired. Furthermore, the same vacuumis operative to apply suction to the suction tubes 83 when thehorizontal transfer plate-76 is in the position of FIG. 12, the ends oftubes 83 then being seated on surface 75 of the vertical transfer plate69. As described above, this suction draws the inserts 21 through tubes83 from the insert supply apparatus 61-61a.

When the vertical transfer plate 69 is in the discharge position shownin FIG. 2, the valve means 95 (FIG. 11)

is momentarily-shifted from the illustrated position to the position atwhich the vacuum source is blocked, and the pressure source 96communicates with port 95a and thus with the associated passages. Thiscondition prevails for only a fraction of a second, and'causes a blastof air to pass through port 95a and passages 93, 92 and 91 (FIG. 13) topassages 89 and thus to nests 88, thereby forcibly ejecting the inserts21 from such nests and propelling them through the air gaps to the seatmeans disposed opposite thereto (FIG. Stated more definitely, the seatmeans comprises the distal ends of the core pins 40 and which arespecifically adapted to-maintain the inserts 21 seated, as describedunder the following subheading.

The passages 89 are long in comparison to their diameters, havinglengths many times their diameters, in order that the air blaststherethrough will be substan tially laminar. Each laminar air blast isdirected to the center of each associated nest 88 to thus effectivelypropel the insert 21 through the air without tending to cause the sameto tumble. It is emphasized that the insert 2] flies rim-first orbackwardly, as shown in FIG. 10, and that aerodynamic and other factors(including the relatively nose-heavy weight of the insert) tend to causeit to tumble in the air as is not desired.

It is important that uniform'air blasts be delivered simultaneously toall inserts in all of the nests 88. It is for this reason that thearrangement shown in FIG. 13 is provided, the port a being centrallylocated and communicating through large and uniform passages with all ofthe passages 89 which extend to the nests 88. Since the air blasts arereceived simultaneously at each nest 88, there is no undesired ventingof air with consequent uneven effects relative to the various inserts.

VACUUM OR SUCTION MEANS (AND METHOD) FOR COOLING THE CORE PINS 40 ANDFOR MAINTAINING INSERTS 21 'SEATED THEREON Referring particularly toFIGS. 8, 10 and 5, each of the core pins 40 is caused to be hollow,there being a bore 100 formed axially therethrough and terminating in acentral opening 101 at the extreme distal end of the pin. Furthermore,as shown in FIG. 8, the case or proximal end of each core pin 40 isprovided with an O-ring seal 102 and seated on a manifold plate 103.Such plate 103 has a plurality of passages 104 communicating with therespective bores 100 and also has a manifold passage 106 whichcommunicates with the aboveindicated vacuum or suction source 57. Suchsource 57 is a source of relatively high vacuum, such as twenty inchesofmercury, and may be the same source indicated at 95b in FIG. 11.

Suction is thus applied continuously to the core pin bores 100 andeffects continuous sucking of air into openings 10] and through thebores 100, thereby effectively cooling the core pins despite the absenceof any cooling water passages. The necessity for providing cooling wateron the ejector side of the mold is thereby eliminated, with consequentsubstantial simplification of the design of the molding apparatus.

It is emphasized that the cooling of the core pins is highly importantsince, unless the core pins are cool when the plastic is injected intothe molding cavities, the plastic will not solidify rapidly. The moldcycle time would, in the absence of effecting cooling, be greatlyincreased, with consequent large reduction in the production rate ofeach molding apparatus. As above indicated, the present moldingapparatus has a cycle time on the order of fifteen seconds, includingall of the loading and ejecting functions and including the timerequired for the plastic to solidify in the mold.

As best shown in FIG. 10, the portion of the mold which provides a seatfor the insert 21, after the same has been propelled out of nest 88, isthe extreme distal end of the core pin 40. Such distal end has a beveledor conical surface 107 the angle of which corresponds tothe angle of theinterior surface 23 of insert 21. The included angle represented in FIG.10 relative to surface 107, and also surface 23, is preferably about 15degrees (each of the indicated inclined lines being seven and one-halfdegrees from the horizontal).

When the inserts 21 seat on the surfaces 107', the dif-- ferential inair pressure is immediately created thereacross due to the applicationof suction to bores 100, and this differential in air pressure maintainsthe inserts firmly in seated positions until after the core pins (withthe inserts thereon) have been introduced into the mold cavities andseated on the plunger means 58 as shown in FIG. 9. This is similar tothe operation whereby the inserts are maintained seated in the nests 88due to the air pressure differential thereacross created by applicationof suction to the passages 89.

THE PLUNGER APPARATUS 88 (AND ASSOCIATED METHOD) With particularreference to FIGS. 8 and 9, there is provided coaxially at the inner endof each mold cavity 38 a hollow plunger or plug 109 which is slidablymounted in a corresponding recess in mold element 37. Each such plungerhas a neck 110 which extends slidably through a bore in mold 37, suchbore communicating coaxially with the inner end of the cavity 38 andhaving a diameter substantially smaller than that of such cavity.Accordingly, a shoulder 11 1 is provided at the intersection of the boreand the cavity 38.

Shoulder 111 has a sharp circular edge which is firmly abutted by acentral region of insert 21, thereby providing an effective seal againstleakage of plastic out of cavity 38. Referring to FIG. 10, the portionof seat 107 is annularly recessed at U, and directly opposite the statedsharp edge, to permit flexing of the insert body under the very largeforces present in the press. It is therefore assured that the requiredseals will be formed without any damage to the inserts.

A strong helical compression spring 112 is mounted in the plunger 109and normally maintains the plunger in its extreme left position as shownin FIG. 8, in engagement with a stop surface 113. However, upon completeinsertion of the core pin 40 (with insert 21 thereon) into the cavity38, the inner end of the insert 21 engages the end of neck 110 andcauses retraction of the plunger 109 against the bias of spring 112. Theinsert is thus introduced sufficiently far to create the above-statedseal at shoulder 111. The plunger is sufficiently short that it neverbottoms on a manifold plate described below.

A passage 114 is provided through the neck 110 and through plunger 109,thus effecting communication between the core pin bore 100 (FIG. 8) anda port 115 when there is no insert 21 on the core pin end. The port 115is present in a manifold plate 116 having a manifold passage 117therein, such passage communicating (when no insert is present) with thefluidics means 59 (FIG. 5) as described in the above-cited copendingpatent application. The fluidics means 59 senses when an insert isabsent when it should be present, and also senses when an insert ispresent when it should be absent.

The outer end of neck 110 is provided with a suitable seat or bevel,indicated at 118, adapted to seat the nose of the insert 21.

In operation, the plunger is engaged and retracted by the insert 21during introduction of the core pin 40 into the cavity 38 as describedabove, following which the insert seats on the shoulder 111 to providethe seal. Thereafter, plastic is introduced into the cavity 38 to fillthe same without flowing into the fluidics portion of the apparatus. Itfollows that the nose region of the insert will be exposed whereas therim of the insert will be embedded in the plastic body 24 (FIG. 7) ofthe probe cover.

SUPPLY MEANS 61 AND 61a (AND METHOD) Proceeding next to a description ofthe insert supply means indicated generally at 61 and 61a in FIG. 1, andshown in detail in FIGS. 17-19, the lower -ends of the suction tubes orconduits 83 are mounted in a row, for example by means of theillustrated mounting block 120. The extreme lower end of each tube isdisposed in the same plane as is the extreme lower end of each othertube, such lower ends being cut off perpendicularly to the tube axes.All 16 of the tubes (for the 16- cavity mold) are indicated in FIG. 1,it being understood that the tubes and associated elements are identicalrelative to each mold cavity so that less than 16 may be shown in FIGS.17-19.

An elongated comb 121 is disposed in spaced relationship beneath theplane of the lower ends of the tubes 83, and parallel to such plane. Thedegree of spacing is such that the suction applied to the tubes 83 asdescribed above is insufficient to draw into the tube ends the inserts21 therebeneath, until after such inserts have been mechanically liftedas described hereinafter. To prevent the suction from disturbing theinserts, the spacing between the lower ends of the tubes and the uppersurface of the comb should be equal to about three or four insertlengths.

One edge of the comb 121 is provided with a row of pockets 122 each ofwhich is sized to receive one and only one insert 21 when the insert isin upstanding inverted relationship as illustrated. The inserts arereferred to as being generally cup-shaped and inverted since the rim ofthe cup faces downwardly. Such pockets have openings or mouths 123 whichpermit the inserts to move transversely into pockets 122 from a row ofinserts. The pockets are sufficiently deep that each insertsubstantially completely fills the associated pocket in which it isdisposed.

The indicated row of inserts is provided on the upper supporting surface124 of a support plate 125, which supporting surface is immediatelybeneath the comb 121. The inserts when moving in the indicated row alongsuch support surface 124 are in abutment either with inserts 21 alreadydisposed in the pockets 122, or else with abutment surfaces 126 whichare provided at the ends of the teeth 127 of the comb 121. Such abutmentsurfaces 126 are substantially parallel to the row of inserts 21.Alternately, and as described below, some of the inserts in the row(outside the comb pockets) are in abutment with combination gate andlifter elements when the latter are in their upper positions as shown inphantom lines in FIGS. 18 and 19.

It will thus be seen that the inserts 12 are disposed in a first rowwhen they are outside the comb, and are disposed in a second row whenthey are in the pockets 122 in the comb, such second row being parallelto the first row and laterally offset therefrom. When in the second row,the inserts in the pockets 122 are beneath the lower ends of the suctiontubes or conduits 83, such lower ends being respectively registered withthe pockets 122.

Combination lifter and gate elements, indicated above, are provided inthe form of fingers or pins 128 which extend upwardly through bores 129in support plate 125, the diameters of the pins being much smaller thanthe sizes of the pockets 122 whereby the bores 129 will not interferewith support or movement of the inserts 21 on support surface 124. Eachpin 128 is registered with the center of an associated pocket 122.

The fingers or pins 128 are mounted on a connector bar 130 which is, inturn, pivotally supported on lever means 131, the latter being pivotedor fulcrumed at shaft 132 on a support block 133. Actuator means, suchas the illustrated cylinder 134, is adapted through connector means 135to pivot the lever means 131 and thereby lift the bar 130 and all of thefingers or pins.

The upper ends of the pins then enter the open bottoms of the invertedcup-shaped inserts, and lift such inserts to the positions shown inphantom lines in FIGS. 18 and 19. The suction applied to the tubes 83 asdescribed above is then sufficient to suck the inserts off the pins andthereafter draw the inserts through the tubes 83 to the seated positionsin the nests in vertical transfer plate 69 (FIGS. 12 and The cylinder134 is controlled by suitable control means, shown in block fonn at 136in FIG. 17, and which is part of the over-all control system mentionedabove. The pins 128 move upwardly sufficiently far that the rims of theinserts substantially reach the plane of the lower ends of the tubes.

The row or inserts shown at the left in FIG. 17, and which is disposedoutside of and adjacent the comb 121, moves continuously along such comband longitudinally thereof due to the operation of a vibrator means 137which is associated with the plate 125 and effects continuouslow-amplitude vibration thereof. Such vibration causes the row ofinserts 21 to move along the comb (in a direction to the right as ivewedin FIG. 17) due to the fact that the upper support surface 124 isinclined somewhat from the horizontal, so that the inserts move downhill. Referring to FIG. 18, the line 138 represents the horizontalwhereas the line 139 is disposed in the same plane as the upper surface124 of plate 125. The angle of incline indicated by lines 138 andl39,may be approximately three degrees.

Correspondingly, the upper surface 124 is inclined in a direction atright angles to the longitudinal incline de scribed relative to FIG. 18,and as 'shown in FIG. 19. Thus, in such FIG. 19 the line 140 representsthe horizontal whereas the line 141 represents the incline of the uppersurface 124, such incline being sloped downwardly toward pockets 122whereby the vibrating plate 125 will tend to cause the inserts to enterthrough openings 123 into pockets 122. Such incline may be, for example,approximately nine degrees.

The inserts 21 are fed to the left end of the row in FIG. 17 from avibratory feeder bowl 142 which may be of various constructions.Reference is made to column 24 of US. Pat. No. 3,293,693, starting atline 7 and ending atline 25. Such portion of US. Pat. No. 3,293,693, thedrawings referred to in such portion, and the patents cited in suchportion, are hereby incorporated by reference herein as though set forthin full.

In the operation of the feeding apparatus of FIGS. 17-19, the vibratoryfeeder bowl supplies inserts continuously to the left end of the rowillustrated in FIG. 17, following which the vibration of plate 125 andthe incline of the surface 124 cause the inserts to pass continuouslyand progressively down hill to the right in FIG. 17 as indicated by thearrow therein. The continuous feeding causes many inserts to pass alongthe full length of the comb 121 following which such inserts arerecycled back to the feeder bowl 142.

Assuming that there are inserts initially in the pockets 122 as shown inFIG. 17, such inserts in the pockets cooperate with the verticalabutment surfaces 126 at the ends of teeth 127 to support the inserts inthe row against lateral movement, whereby the inserts continue to travelto the right as is desired. It is emphasized that 14' portions of theinserts are distinguished from the lower portions thereof.

Upon operation of cylinder 134 by control means 136 to lift the pins 128simultaneously, the pins lift the inserts up into the suction tubes asstated above. While the pins 128 are in their upper positions, shown inphantom lines in FIGS. 18 and 19, the inserts in the row adjacent thecomb continue to move to the right as indicated by the arrow. Thoseinserts which are adjacent the pockets 122 may move partially thereinbut they cannot fully enter the pockets due to the presence of theupwardly shifted pins 128. After partially entering the pockets, theinserts move out of the pockets and continue moving in the row (not inthe comb or in the pockets), particularly since the corners of the teeth127 are beveled to prevent the inserts from hanging up on such corners.It follows that the pins 128 not only lift the inserts 21 but operate asgates to prevent full entrance of the inserts into the pockets, so thatthe inserts continue moving in the row and do not tip over.

After the pins 128 shift down to their lower positions, out of thepockets 122, the inserts in the row thereof and which are registeredwith the various pockets pass laterally therein due to the incline shownin FIG. 19

- and due to the vibration of plate 125. Those inserts which do notenter the pockets continue moving in the row. The operation is thusrepeated and the pins lifted to cause the pocketed inserts to be liftedup to the suction tube ends.

It is pointed out that the pins cannot lift any inserts which may bedisposed in pockets in upright as distinguished from inverted condition.Thus, the mechanism operates to prevent inserts fromentering the ends oftubes 83 open end first instead of nose first which is desired.

The feeding of the inserts through the suction tubes 83 one at a time,as distinguished from passing stacks of inserts through the tubes, ishighly important in that nesting of the inserts is prevented.

Because the inserts are drawn through the tubes by suction, not bypressure, the inserts may be readily lifted for far greater distances.Thus, and as indicated above, the insert-feeding mechanism 61-6la may bedisposed at a relatively low elevation, for example on the floor next tothe molding machine, and is isolated therefrom except by the plastictubes 83 which bend sufficiently to prevent transmission of shock fromthe molding machine into the feeder bowl. Thus, the feeder bowl andfeeder mechanism is not jarred to thereby disturb the extremely lightand top-heavy inserts.

the increased thickness of metal (FIG. 10) at the upper BRIEF SUMMARY OFOPERATION Let it be assumed-that the apparatus is initially in thecondition shown in FIGS. 1 and 5, the mold being fully open. Let it alsobe assumed that there are inserts 21 located in all of the nests 88 invertical transfer plate 69.

The control circuit associated with the molding press then gives asignal to the loader control means 73 (FIG. 1), causing the cylinder 64to shift the vertical transfer plate 69 downwardly to the position shownin FIG. 2. The valve (FIG. 11) is then operated to the position oppositethe one shown, causing the pressure source 96 to be connected to nests88 to thereby propel the inserts 21 through the air to the ends of corepins 40, as shown in FIG. 10, following which the valve 95 shifts backto its vacuum position causing vacuum to be applied to all the nests.

The loader control means 73 (FIG. I) then operates to shift verticaltransfer plate 69 upwardly to the position of FIGS. 1 and 4.

The molder control means 34 (FIG. 1) is then operated to cause thecylinder 32 to close the press to the position shown in FIGS. 6 and 9,the core pins 40 entering the mold cavities 38 and effecting depressionof the sealing plunger means 58 as described relative to FIGS. 8 and 9.

Assuming that the fluidics 59 (FIG. 5) then senses that all inserts areproperly positioned, the injection control means 36 (FIG. 2) is operatedto inject plastic through the elements 35 (FIG. 2), 53 (FIG. 14), 42 and43 into cavities 38 to fill the same. The cooled core pins 40 and thecooling means associated with the mold element 37 then cause rapidsolidification of the plastic.

During injection of the plastic, the fingers 128 (FIGS. 17-19) arelifted by cylinder 134 under the control of control means 136 to liftinserts 21 out of pockets 122 into suction tubes 83. There is thensuction present in such tubes due to the fact that the lug 82 on movingplaten 31 then engages pin 81 (FIG. 4) to shift the horizontal transferplate 76 sufficiently far to cause the tube ends to seal around thenests 88 as shown in FIG. 12. The suction applied through passage 89then operates through tubes 83 to suck the inserts into the nests.

At the end of the predetermined time sufficient to cause solidificationof the plastic, the press is opened under the control of molder controlmeans 34 (FIG. 1), following whichthe stripper control means 49 (FIG. 2)operates the cylinder 47 to shift the stripper plate 46 forwardly andeffect ejection of parts from the press as described relative to FIGS. 7and 14-16. In the event' that the stripping is not effective, the nextdownward movement of the vertical transfer plate 69 operates throughlugs S to insure that stripping occurs.

The cycle is then repeated, it being emphasized that air is continuouslysucked through the core pins 40 at all times (except when there areinserts mounted over the openings 101 in the ends thereof) to effectcooling of the core pins as is important for minimized cycle time.

References to vertical" and horizontal in the appended claims, relativeto the vertical and horizontal transfer plates, are not intended to belimitations relative to such directions since such claims are notavoidable by changing the orientation of the molding apparatus and theassociated loader. The words vertical" and horizontal" are used, inconnection with such plates, to generally indicate relative directions.

We claim:

1. Apparatus for feeding small objects, which comprises:

a vertical transfer means having seat means in an exterior surfaceportion thereof.

means to move said vertical transfer means generally vertically betweena loading position and a discharge position,

a horizontal transfer means disposed in the vicinity of said verticaltransfer means when the latter is in said loading position,

means to move said horizontal transfer means generally horizontallybetween a first position at which said horizontal and vertical transfermeans are clear of each other and a second position at which saidhorizontal transfer means is adjacent said vertical transfer means whenthe latter is in said loading position,

conduit means having end portions associated with said horizontaltransfer means for movement therewith, said end portions of said conduitmeans seating respectively around said seat means on said verticaltransfer means when said horizontal transfer means is in said secondposition,

suction means to apply suction to said seat means,

whereby suction is also applied through said seat means to said conduitmeans when said horizontal transfer means is in said second position,means to introduce small objects into said conduit means, through theend portions thereof remote from said first-mentioned end portions, whensaid horizontal transfer means is in said second position,

whereby said objects are sucked through said conduit means to said seatmeans and are retained on said seat means by suction, and

means to discharge objects from said seat means when said verticaltransfer means is in said discharge position.

2. In a method of molding parts having inserts therein, the steps of:

providing a multiplicity of seat means having airintake openingstherein,

drawing air through said air-intake openings to thereby create suction,

providing a multiplicity of conduit ends spaced from said seat meanssufficiently far that the suction present at said openings does notcreate substantial suction in said conduit ends,

moving said conduit ends into engagement with said seat means and insuch manner that the suction present in said openings will createsubstantial suction in the conduits associated with said conduit ends,and

employing said suction in said conduits to draw said inserts throughsaid conduits,

whereby said inserts are caused to seat on said seat means and remainthereon due to the differential in pressure across said inserts.

1. Apparatus for feeding small objects, which comprises: a verticaltransfer means having seat means in an exterior surface portion thereof,means to move said vertical transfer means generally vertically betweena loading position and a discharge position, a horizontal transfer meansdisposed in the vicinity of said vertical transfer means when the latteris in said loading position, means to move said horizontal transfermeans generally horizontally between a first position at which saidhorizontal and vertical transfer means are clear of each other and asecond position at which said horizontal transfer means is adjacent saidvertical transfer means when the latter is in said loading position,conduit means having end portions associated with said horizontaltransfer means for movement therewith, said end portions of said conduitmeans seating respectively around said seat means on said verticaltransfer means when said horizontal transfer means is in said secondposition, suction means to apply suction to said seat means, wherebysuction is also applied through said seat means to said conduit meanswhen said horizontal transfer means is in said second position, means tointroduce small objects into said conduit means, through the endportions thereof remote from said firstmentioned end portions, when saidhorizontal transfer means is in said second position, whereby saidobjects are sucked through said conduit means to said seat means and areretained on said seat means by suction, and means to discharge objectsfrom said seat means when said vertical transfer means is in saiddischarge position.
 2. In a method of molding parts having insertstherein, the steps of: providing a multiplicity of seat means havingair-intake openings therein, drawing air through said air-intakeopenings to thereby create suction, providing a multiplicity of conduitends spaced from said seat means sufficiently far that the suctionpresent at said openings does not create substantial suction in saidconduit ends, moving said conduit ends into engagement with said seatmeans and in such manner that the suction present in said openings willcreate substantial suction in the conduits associated with said conduitends, and employing said suction in said conduits to draw said insertsthrough said conduits, whereby said inserts are caused to seat on saidseat means and remain thereon due to the differential in pressure acrosssaid inserts.